DEVELOPMENT OF LOW-COST VISIBLE SPECTROPHOTOMETER TO IMPROVE STUDENTS’ CHEMICAL ANALYSIS SKILLS IN SCHOOLS

• Main Author: Agustina, Andri
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/55393
• Institution: Institut Teknologi Bandung

The absorption spectroscopy technique is widely used because it is relatively simple and practical for chemicals study of substances. The spectrophotometer is an important laboratory instrument for qualitative and quantitative chemical analysis. However, most of the senior high schools do not yet have this tool. Because commercial spectrophotometers are expensive. This study aims to develop a low-cost spectrophotometer for students with an RGB LED light source, photodiode BPW34, and an Arduino nano. This device has dimensions of 18.5 cm x 11.5 cm x 6.5 cm. The absorbance calibration was carried out using a standard solution of CuSO4.5H2O, obtained an average absorbance of 0,205 with an error percentage of 8,66%. Linearity test on brilliant blue and alizarin red s, linearity (R2) values of 0.9992 and 0.9951. LOD and LOQ of brilliant blue FCF and alizarin red s 0.3189 mg.L-1, 0.9665 mg.L-1 and 0.4583 mg.L-1, 1.3888 mg.L- 1. The results of the t-test (paired sample t-test) for brilliant blue obtained a significance value of 0.075> 0.05 (0-100 ppm), and alizarin red s obtained a significance value of 0.154> 0.05 (0 - 5 ppm) with the 95% confidence. This value indicates that there is no significant difference with the Genesys-10 UV-Vis spectrophotometer. The low-cost spectrophotometer has been made can be used to determine the concentration of brilliant blue and alizarin red s, so that it can be used in learning chemical analysis in senior high schools.